This invention relates to motor vehicle antennas and more particularly to apparatus for ensuring the proper interconnection of a replacement power antenna with existing vehicle componentry.
Typical universal power replacement antennas include an antenna relay in the package for effecting the switching control over the antennas motor for driving the antenna between extended and retracted positions. In the usual application, the replacement antenna is designed for actuation from a remote switching device provided either by a toggle switch actuated mechanically by the operator of the vehicle or semi-automatically by an internal switch in the radio of the vehicle which is actuated when the radio is turned on and off. In this application, the interchange of a replacement antenna is fairly convenient as the reversing circuitry is replaced as well with the interchange of the antennas and only a simple wire interconnection is required.
In some applications however, the antenna relay itself is remote from the antenna and is more closely associated with the vehicle radio, usually being located beneath the dashboard of the vehicle and in an inconvenient location. These systems are designed for replacement antennas that only include the antenna and drive motor since it is expected that the original antenna relay will be retained.
In trying to mate such a system however, with a universal replacement antenna, it is obvious that difficulties are encountered as two sets of antenna relays will be included in the system and it will be impossible to provide the proper switching signals by a simple interconnection of components. As noted, it is difficult and inconvenient to gain access to the original equipment relay since it is beneath the dashboard. However, in the past, such procedure was required or alternatively, a specially designed replacement antenna was required. This obviated the advantages of a universal replacement antenna which would be suitable for all situations and which could accordingly be obtained at an advantageous price.
One typical design of prior art antenna is shown in U.S. Pat. No. 2,695,957 which shows a projectable antenna and the associated electrical switching circuitry therefor. This type of circuity is designed primarily for manual actuation.
In U.S. Pat. Nos. 2,933,597 and 3,022,420, control circuits are described for power antennas. These circuits include control relays and describe how the relays may be energized concurrently with actuation of the associated radio or other receiver.
U.S. Pat. No. 3,873,985 shows yet another version of power antenna and the electrical switching mechanism therefor. In this showing limit switches are described in detail, these being microswitches activated at either end of travel of the antenna rod.